Not sure what went wrong-I have dual batt w/ perko switch. When xm is on and I start the boat it automaticly shuts xm off-not the stereo though. If a cd is playing no problem. Its wired to constant hot.Any suggestions will help. thanks all

Paul you are probably wired to a constant hot that does not stay hot during the Cranking cycle. you can check this really easy, get a test light or multimeter and check the wire while you are starting the boat. It will probably not have power at that point. Find the ignition wire, which will stay hot during cranking.